Earthquakes Induced by Fracking in Oklahoma
GLIS 657: Data Science Assignment 3 Alex Nawotka
1. Introduction
Purpose
This report seeks to demonstrate the relationship between earthquakes and the hydraulic fracturing process through data analysis and visualization to aid writers, journalists, curriculum developers, and public educators in the development of informative communications. Further iterations of this report could be modified for use in public education at museums, state parks, schools, online, in homeschool curriculum guides, and via other media outlets in Oklahoma. It is crucial that the results of this research be effectively communicated in a way that is accessible to the communities of residents, oil industry workers, policymakers, and especially all of their children who hold the agency and potential to advocate sustainable changes in oil and gas extraction practices.
The study was guided by the following inquiries: 1. Is there a correlation between earthquakes (event time, location, magnitude, depth) in Oklahoma and the disposal of wastewater produced by oil and gas extraction (well injection location, volume, depth, pressure)? 2. How can data visualization aid in educating Oklahoma residents and policy makers about the seismic risks resulting from fracking and expand their concept of the fracking process to include wastewater disposal?
Background
Within the past decade, there has been an influx of climate research and media coverage interrogating the relationship between changes in seismic activity and the increase of hydraulic fracturing (fracking) as a method of oil and gas extraction. Ranked as the third largest US producer of natural gas in 2018 (OERB), the state of Oklahoma is also home to a 900~ fold increase in earthquakes since 2009 (Hinks et al., 2018). The increase in earthquake frequency in Oklahoma is widely accepted among researchers to be induced by fluid injection depth (Hinks et al., 2018; Keranen et al., 2014; Rubinstein & Mahani, 2015; Skoumal et al., 2018; Walsh & Zoback, 2015). (Jones, 2016; Lacey, 2011) (Ellsworth, 2013; Holland, 2013; Keranen, Savage, Abers, & Cochran, 2013; McGarr et al., 2015; Mcnamara et al., 2015c; McNamara et al., 2015a,2015b).
Although fracking does involve injecting fluid and materials into the earth, it produces a highly saline “flow-back” water (Hinks et al., 2018; Walsh & Zoback, 2015). This water is typically disposed of at class II underground injection control (UIC) wells and may be combined with other water contaminated through oil and gas production (EPA, 2019; OCC 2019; Rubinstein & Mahani, 2015). UIC wells are deeper than hydraulic fracturing wells, so the wastewater is injected deeper into the earth than the fluid used in fracking. As the earthquake correlation is dependent on the depth of fluid injection, there is a stronger association between earthquakes and wastewater injection than between earthquakes and fracking injection. Acknowledging that (a) the wastewater injected in UIC wells is a byproduct of fracking and (b) the increase in seismic activity, wastewater volume, and fracking activity occurred simultaneously, it’s logical to infer that wastewater injection is a part of the fracking process. Thus, this report seeks to illustrate the impact of the fracking process on seismic activity by analyzing earthquake data provided by the US Geological Society (USGS) and wastewater data provided by the Oklahoma Corporation Comission (OCC).
2. Methodology
Datasets
Two datasets gathered by The United States Geological Survey (USGS) and Oklahoma Corporation Commission (OCC) are used in this study. The first dataset lists earthquakes in the Oklahoma region (Oklahoma and surrounding states) from 1973-2016 downlated from Kaggle. The second dataset is a combination of eight datasets downloaded from the OCC website containing annually collected data about individual class II UIC well activity.
These datasets were selected because they include comparable factors such as specific locations and time ranges of events/activities, which can be used (in addition with other details) to determine correlations, generate time series, and maps to forecast and predict the seismic activity of geographic zones based on indivudal injection well activity. While there are some missing fields in the earlier occurrences, most entries are consistent and complete, and require minimal cleaning. I chose to combine the eight datasets of annual well activity from the OCC website, rather than use the dataset of all well activity included in the Kaggle file (which only recorded an average of all annual well activity into one field) because I wanted to be able to analyze trends in annual well activity. Selecting to work with this data affords the potential to generate geospatial time series visualizations that illustrate the frequency, magnitude, and location of earthquakes in correlation with the location and activity of saltwater injection wells over the same range of time. Additionally, these data sets were freely available via Kaggle and the OCC website.
Earthquakes https://www.kaggle.com/ksuchris2000/oklahoma-earthquakes-and-saltwater-injection-wells
UIC Wells https://www.occeweb.com/og/ogdatafiles2.htm
Information about Column Names from USGS https://earthquake.usgs.gov/data/comcat/data-eventterms.php
Features and Processing
Prepare and Subset Data
| date_time | latitude | longitude | depth | mag |
|---|---|---|---|---|
| 2005-10-10 04:18:06 | 40.572 | -106.732 | 5 | 2.2 |
| 2000-02-09 04:09:25 | 40.660 | -106.727 | 5 | 2.5 |
| 2010-12-17 01:31:44 | 36.375 | -106.722 | 5 | 3.0 |
| 1993-07-08 04:26:19 | 39.210 | -106.716 | 5 | 2.6 |
| 1993-07-08 04:03:52 | 39.227 | -106.715 | 5 | 3.1 |
| API | Lat_Y | Long_X | TotalDepth |
|---|---|---|---|
| 3510523611 | 36.71450 | -95.71517 | 125 |
| 3503711183 | 35.96278 | -96.07414 | 152 |
| 3513705933 | 34.42279 | -97.71872 | 168 |
| 3506720940 | 34.28055 | -97.71295 | 195 |
Analytical Method
This report uses spatial mapping models to visualize the indicators evaluated to be significant by research on the same datasets conducted at the School of Earth Science at University of Bristol (Hinks et al., 2018). The advanced Bayesian network they developed to model joint conditional dependencies between spatial, operational, and seismicity parameters pointed to injection depth relative to crystalline basement as the strongest indicator of seismic activity.
Through layering data points on a series of interactive maps, the data visually illustrates the correlation between injection depth and seismic activity. The mapping tool, Leaflet, includes a package for generating density clusters and outlines for emphasizing areas of significance.
K-means clustering has been used to aid in determining break points in wastewater injection depth at UIC wells in 2015. This method of clustering is useful in classifying numerical data into groups. These clusters are then linked to colors used to identify which depth is most closely linked to earthquakes occuring that year in by visualizing them on a map.
3. Implementation and Results
Earthquakes in Oklahoma over time
The first three plots illustrate the increase in frequency, magnitude, depth, and magnitude type of earthquakes in Oklahoma from 1973-2016.
Magnitude Type Descriptions https://earthquake.usgs.gov/learn/topics/mag-intensity/magnitude-types.php 
This histogram zooms in on the activity in years 2009-2016 to illustrate the significant increase in seismic activity during this period.
Mapping
The following interactive maps illustrate the relationship between the earthquakes and injection depth at wastewater disposal wells.
The first map shows the locations of all earthquakes in Oklahoma occurring between 1973-2016 in red (with the option to cluster by density) and the locations of UIC wells in blue.
The second map illustrates the relationship between earthquakes and wastewater injection depth in 2015. The colors are linked to clusters of injection well depth levels. Unfortunately
4. Recommendations
A major falacy in the narrative presented by USGS is that the disposal of wastewater produced at all oil wells (hydraulic fracturing sites, as well other conventional rigs) is not a part of the fracking process. This could be a potential domain for a future mixed-methods study integrating a qualitative approach the disciplines of sociology, economics, political science, and media and cultural studies and text analysis to argue for widespread acceptance of this falacy as an attribute of the socioeconomic situation and low education resulting from the industrial history of tax policy development and public education funding and curriculum development.
https://www.americangeosciences.org/critical-issues/faq/what-underground-injection-wells-used
5. Conclusion
Despite acceptance of wastewater injection as a part of the fracking process among researchers, it is necessary to consider the implications of these research results on non-researchers who are affected by the earthquakes and the fracking process. The same research findings have been cited by the oil and gas industry and the US Geological Society to justify the continuation of their tax-evading drilling practices by detaching environmental impact from the fracking process (See Fig. 1 & 2; Oklahoma Policy Institute, 2019; USGS, 2019; Rubinstein & Mahani, 2015). These industry sources are viewed as “reliable” by public educators, news media, US policymakers, and government officials and their interpretation of the research is widely accepted by the general Oklahoma public (Murphy et al., 2018). By only referring to “wastewater”, the writers misinform the public by isolating any mention of wastewater from the fracking process. This argument justifies the continuation of their environmentally destructive profit boom by detaching environmental impact from the fracking process (Cohen & Schneyer, 2016; OERB, 2019; Rubinstein & Mahani, 2015; USGS, 2019; Zou & Wertz, 2017). Whether the slated misinformation is propogated by (a) strategic citation used to divert and de-escalate public awareness of seismic risk to appease the myopic industry dominating Oklahoma’s economy (See Fig. 3 &4 ; OERB, 2019; Rubinstein & Mahani, 2015; USGS, 2019), (b) greed and stress-induced mental fog, (c) poor education due to the drop in education funding after the oil industry tax cuts (See Fig. 5; Cohen & Schneyer, 2016; Farmer, 2017) and the science curriculum provided to 98% of Oklahoma schools by the industry-funded Oklahoma Energy Resources Board (Zou & Wertz, 2017), or (d) a multiplicitous, fluid intersection of complex variables spanning socioeconomics, political stress, culture and lifestyle, psycho-geological trauma responses to the frequent tornadoes, earthquakes, and wildfires - one thing is clear: Change in the way research results and narratives are communicated to the communities they affect is necessary.
Fig. 1: An infographic showing the causes and consequences of induced seismicity in the U.S. State of Oklahoma. (Gernon, 2018)
Fig. 2: United States Geological Survey (USGS, 2019)
Fig. 3: Cost of oil and gas tax breaks 2014-2019 (Oklahoma Policy Institute, 2019)
Fig. 4: Oklahoma Oil Production Growth 2006-2016 “Sources: EIA; Oklahoma Tax Commission” (Cohen & Schneyer, 2016)
Fig. 5: Oklahoma Education Budget Decrease 2008-2016 (Cohen & Schneyer, 2016)
Bibliography
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EPA - US Environmental Protection Agency. Underground Injection Control (UIC): Class II Oil and Gas Related Injection Wells. https://www.epa.gov/uic/class-ii-oil-and-gas-related-injection-wells
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OCC - Oklahoma Corporate Commission. (2019) What Can be Put Down a Class II Injection Well? Retrieved from https://www.occeweb.com/og/What%20Can%20be%20Put%20Down%20a%20Class%20II%20Injection%20Well.pdf
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Media
https://www.eia.gov/state/?sid=OK#tabs-3
https://www.cbpp.org/research/state-budget-and-tax/a-punishing-decade-for-school-funding
https://www.theguardian.com/news/2018/aug/30/how-the-us-fracking-boom-almost-fell-apart
https://www.bls.gov/oes/current/naics3_211000.htm
https://www.rigzone.com/news/us_oil_and_gas_employment_up_54_in_2018-11-feb-2019-158126-article/
https://newsok.com/article/5606608/point-of-view-the-rest-of-the-story-about-fracking
https://stateimpact.npr.org/oklahoma/2017/06/15/oils-pipeline-to-americas-schools/
https://www.theguardian.com/us-news/2017/jun/15/big-oil-classrooms-pipeline-oklahoma-education
https://www.governing.com/topics/education/gov-oklahoma-states-education-funding.html
https://www.governing.com/gov-data/education-data/state-education-spending-per-pupil-data.html